IV. 2MASS Data Processing


5. Extended Source Identification and Photometry

a. Algorithms, Analysis and Results

viii. XSC -- Virgo Galaxy Cluster: Full-Resolution, 3 deg2 Mosaic

In order to test the XSC completeness at fainter and more compact scales, we employ a full-resolution mosaic of the "heart of Virgo," as seen in Figure 1 (J-band; note M87 in lower left corner). This mosaic has 1´´ pixel size, with an image size of 8000 × 5100 pixels, for a field-of-view of 2.2° × 1.4°.

Figure 1

Results

The Virgo full-resolution mosaic was split into 60 pieces, each 800×900 pixels (approximately 40´ on a side). In Figures 2-61, in Table 1 below, the 2MASS working database extended sources are marked with blue circles, and the XSC sources with green circles. The 2MASS Point Source Catalog (PSC) are marked with orange circles. Finally, sources found in the NED database are marked with magenta diamonds (presumably these are Virgo Cluster galaxies).

The sub-images were then visually inspected, concentrating on clearly-delineated Virgo galaxies which are not in the XSC (i.e., source not circled in green). These sources (at least the ones with measured SNR > 7) represent incompleteness in the XSC. Table 1 presents the 10×6 grid of subimages. (Items to note: "chaff" in proximity to large and bright galaxies is mostly eliminated from the XSC; artifacts from bright stars; airglow and background gradients; source confusion; faint or compact sources provide little if any information for this experiment.)

Table 1
  1 2 3 4 5 6 7 8 9 10
1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11
2 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 Figure 17 Figure 18 Figure 19 Figure 20 Figure 21
3 Figure 22 Figure 23 Figure 24 Figure 25 Figure 26 Figure 27 Figure 28 Figure 29 Figure 30 Figure 31
4 Figure 32 Figure 33 Figure 34 Figure 35 Figure 36 Figure 37 Figure 38 Figure 39 Figure 40 Figure 41
5 Figure 42 Figure 43 Figure 44 Figure 45 Figure 46 Figure 47 Figure 48 Figure 49 Figure 50 Figure 51
6 Figure 52 Figure 53 Figure 54 Figure 55 Figure 56 Figure 57 Figure 58 Figure 59 Figure 60 Figure 61

Missing Galaxies

Table 2 presents the sources identified from the Virgo mosaic that do not have an XSC counterpart. The columns for the table are: (ip,jp), panel number, from Table 1 above; (x,y), pixel coordinates; (ra,dec), J2000 equatorial coordinates; radius, circular aperture radius in arcsec; J mag; J-band rms uncertainty; and, "zoomed" image.

Table 2
IP JP x y ra dec radius ba pa ib mag dmag image
2 1 1532.0 4876.0 187.64738 13.62123 7.0 1.000 0.0 j 15.606 0.166 Figure 62
4 1 2455.0 4475.0 187.38193 13.50986 7.0 1.000 0.0 j 16.370 0.335 Figure 63
5 1 3725.0 4718.0 187.02057 13.57827 7.0 1.000 0.0 j 15.307 0.127 Figure 64
5 1 3542.0 4255.0 187.07278 13.44991 7.0 1.000 0.0 j 15.759 0.191 Figure 65
6 1 4750.0 4674.0 186.72766 13.56625 7.0 1.000 0.0 j 14.976 0.094 Figure 66
9 1 6546.0 5069.0 186.21410 13.67506 7.0 1.000 0.0 j 16.010 0.240 Figure 67
10 1 7328.0 4579.0 185.99107 13.53795 7.0 1.000 0.0 j 15.777 0.194 Figure 68
3 2 2176.0 3506.0 187.46249 13.24109 7.0 1.000 0.0 j 16.138 0.270 Figure 69
3 2 2192.0 3464.0 187.45790 13.22943 7.0 1.000 0.0 j 16.125 0.267 Figure 69
4 2 2602.0 3691.0 187.34100 13.29270 7.0 1.000 0.0 j 14.130 0.045 Figure 70
6 2 4701.0 3752.0 186.74188 13.30987 7.0 1.000 0.0 j 15.020 0.098 Figure 71
8 2 5934.0 3456.0 186.39011 13.22714 7.0 1.000 0.0 j 15.450 0.144 Figure 72
8 2 5689.0 3350.0 186.46008 13.19783 7.0 1.000 0.0 j 15.042 0.100 Figure 73
1 3 37.0 2930.0 188.07220 13.07917 7.0 1.000 0.0 j 15.796 0.198 Figure 74
3 3 1998.0 2945.0 187.51292 13.08515 7.0 1.000 0.0 j 16.223 0.292 Figure 75
4 3 2782.0 2828.0 187.28929 13.05277 7.0 1.000 0.0 j 15.587 0.163 Figure 76
4 3 2659.0 3099.0 187.32448 13.12827 7.0 1.000 0.0 j 16.308 0.316 Figure 77
6 3 4304.0 2501.0 186.85532 12.96243 7.0 1.000 0.0 j 16.010 0.240 Figure 78
7 3 5194.0 2512.0 186.60162 12.96528 7.0 1.000 0.0 j 14.986 0.095 Figure 79
7 3 5473.0 3081.0 186.52184 13.12322 7.0 1.000 0.0 j 15.810 0.200 Figure 80
8 3 6324.0 2911.0 186.27922 13.07549 7.0 1.000 0.0 j 16.356 0.330 Figure 81
9 3 6853.0 3190.0 186.12810 13.15257 10.0 1.000 0.0 j 15.166 0.159 Figure 82
9 3 7067.0 2649.0 186.06758 13.00209 7.0 1.000 0.0 j 16.430 0.353 Figure 83
10 3 7271.0 2893.0 186.00916 13.06967 7.0 1.000 0.0 j 15.863 0.210 Figure 83
10 3 7272.0 2782.0 186.00899 13.03911 7.0 1.000 0.0 j 16.167 0.278 Figure 84
1 4 479.0 2166.0 187.94528 12.86774 7.0 1.000 0.0 j 15.689 0.179 Figure 85
1 4 392.0 1866.0 187.96973 12.78403 7.0 1.000 0.0 j 16.108 0.263 Figure 86
2 4 1368.0 1565.0 187.69145 12.70137 7.0 1.000 0.0 j 15.909 0.219 Figure 87
3 4 2094.0 2147.0 187.48506 12.86355 7.0 1.000 0.0 j 18.527 2.432 Figure 88
4 4 2778.0 1785.0 187.29031 12.76360 7.0 1.000 0.0 j 15.844 0.207 Figure 89
5 4 3386.0 2002.0 187.11690 12.82377 7.0 1.000 0.0 j 14.413 0.057 Figure 90
5 4 3701.0 2270.0 187.02718 12.89826 7.0 1.000 0.0 j 15.190 0.114 Figure 91
6 4 4039.0 2133.0 186.93086 12.86022 7.0 1.000 0.0 j 15.630 0.170 Figure 92
6 4 4267.0 1673.0 186.86594 12.73243 7.0 1.000 0.0 j 15.640 0.171 Figure 93
6 4 4441.0 1774.0 186.81638 12.76047 7.0 1.000 0.0 j 15.723 0.185 Figure 94
7 4 5455.0 2137.0 186.52740 12.86100 7.0 1.000 0.0 j 15.339 0.130 Figure 95
8 4 5968.0 1977.0 186.38133 12.81656 7.0 1.000 0.0 j 15.658 0.174 Figure 96
9 4 6557.0 2305.0 186.21327 12.90670 7.0 1.000 0.0 j 15.530 0.155 Figure 97
10 4 7485.0 1651.0 185.94949 12.72472 7.0 1.000 0.0 j 15.168 0.112 Figure 98
10 4 7815.0 1922.0 185.85518 12.79935 7.0 1.000 0.0 j 15.633 0.170 Figure 99
1 5 398.0 778.0 187.96681 12.48181 10.0 1.000 0.0 j 14.511 0.088 Figure 100
1 5 79.0 820.0 188.05763 12.49311 7.0 1.000 0.0 j 15.916 0.221 Figure 100
2 5 1380.0 360.0 187.68706 12.36664 7.0 1.000 0.0 j 13.205 0.024 Figure 101
3 5 1739.0 714.0 187.58521 12.46525 7.0 1.000 0.0 j 15.109 0.106 Figure 102
3 5 2025.0 623.0 187.50378 12.44016 7.0 1.000 0.0 j 15.677 0.177 Figure 103
3 5 2010.0 620.0 187.50806 12.43904 7.0 1.000 0.0 j 15.997 0.238 Figure 103
3 5 2240.0 961.0 187.44281 12.53446 7.0 1.000 0.0 j 15.510 0.152 Figure 104
4 5 2664.0 446.0 187.32195 12.39132 7.0 1.000 0.0 j 16.037 0.246 Figure 105
6 5 4590.0 801.0 186.77411 12.49016 7.0 1.000 0.0 j 16.249 0.299 Figure 106
6 5 4090.0 803.0 186.91637 12.49077 7.0 1.000 0.0 j 15.788 0.196 Figure 107
7 5 4972.0 886.0 186.66512 12.51368 10.0 1.000 0.0 j 14.290 0.073 Figure 108
1 6 75.0 267.0 188.05811 12.33949 7.0 1.000 0.0 j 15.771 0.193 Figure 109
1 6 14.0 195.0 188.07536 12.31941 7.0 1.000 0.0 j 15.653 0.174 Figure 109
1 6 53.0 138.0 188.06421 12.30363 7.0 1.000 0.0 j 15.823 0.203 Figure 110
3 6 2303.0 202.0 187.42448 12.32337 7.0 1.000 0.0 j 15.929 0.223 Figure 111
4 6 2895.0 90.0 187.25612 12.29224 7.0 1.000 0.0 j 15.886 0.215 Figure 112
7 6 5562.0 397.0 186.49776 12.37761 7.0 1.000 0.0 j 15.263 0.122 Figure 113
8 6 5864.0 168.0 186.41228 12.31383 10.0 1.000 0.0 j 14.385 0.079 Figure 114
8 6 6190.0 112.0 186.31906 12.29807 7.0 1.000 0.0 j 15.171 0.112 Figure 115
8 6 6244.0 154.0 186.30396 12.30998 7.0 1.000 0.0 j 16.308 0.316 Figure 115
10 6 7375.0 469.0 185.98206 12.39622 7.0 1.000 0.0 j 15.925 0.222 Figure 116

See the summary of missing galaxies in IV.5a6.

[Last Updated: 2002 Oct 10 ; by T. Jarrett]


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